Document Type and Release Option

Copyright Statement / License for Reuse

Department

Department of Health and Kinesiology

Committee Chair

Li Li

Committee Member 1

Barry Munkasy

Committee Member 2

Tamerah Hunt

Abstract

Context: The definition of the “core” within the literature is misconstrued: some researchers believe the core only involves muscles of the trunk while others believe it also includes muscles of the hip. Core strength tests typically include exercises that activate hip flexors and extensors without a firm definition of the “core” including the muscles of the hip. Purpose: The purpose of this study was to differentiate between the strength of the trunk and hip during flexion and extension.

Methods: Participants included 28 Division I collegiate athletes from a single university (12 males, 16 females, height (in.) = 69.14 ± 4.81, weight (lb.) = 171.57 ± 45.54, age = 20.82 ± 1.31). Trunk and hip joint strength was tested on the Biodex Isokinetic Dynamometer using the hip and the back attachments. Measurements were taken of peak torque isometrically and both peak and average torque isokinetically at contraction speeds 60 deg/s, 120 deg/s, and 180 deg/s. The independent variables are joint, contraction speed, and flexion/extension. The dependent variables are peak and average torque.

Results: One-factor ANOVAs with repeated measures were ran to compare between peak and average torques for both joints at the different contraction speeds. A Tukey’s post hoc analysis was ran in order to control the amount of error within the data. There was a significant interaction between joint and speed for peak isokinetic hip flexion torque (F(1,28)=22.75, p< 0.05), average isokinetic hip flexion torque (F(1,28)=13.93, p< 0.05), peak isokinetic hip extension torque (F(1,28)=32.72, p< 0.05), and average isokinetic hip extension torque (F(1,28)=37.90, p< 0.05). For the isometric tests, there was significance between joints for both flexion (F(1,28)=86.15, p< 0.05) and extension (F(1,28)=66.58, p< 0.05). For all post hoc comparisons of isokinetic tests, trunk strength was significantly different between the different test speeds. For post hoc comparisons of peak and average isokinetic extension torque, hip strength was significantly different from trunk strength at 60 and 120 deg/s. For post hoc comparisons of peak and average isokinetic flexion torque, hip strength was significantly different when compared to the trunk at all testing speeds. Hip strength was significantly different when compared to trunk strength at all testing speeds during peak and average flexion torque. When looking at the post hoc comparison for peak isometric flexion and extension torque in, trunk strength is significantly different when compared to hip strength

Conclusion: Because the trunk and hip joints are different from each other when comparing movement of the two joints at different contraction speeds, researchers must be careful when defining and testing the “core”.